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Fishermen pull on a rope in Port Cite Soleil in Port-au-Prince, Haiti, Friday, Aug. 24, 2012. Tropical Storm Isaac strengthened slightly as it spun toward the Dominican Republic and Haiti, but seemed unlikely to gain enough steam early Friday to strike as a hurricane. The storm's failure to gain the kind of strength in the Caribbean that forecasters initially projected made it more likely that Isaac won't become a hurricane until it enters the Gulf of Mexico, said Eric Blake, a forecaster with U.S. National Hurricane Center in Miami. (AP Photo/Dieu Nalio Chery)

Fishermen pull on a rope in Port Cite Soleil in Port-au-Prince, Haiti, Friday, Aug. 24, 2012. Tropical Storm Isaac strengthened slightly as it spun toward the Dominican Republic and Haiti, but seemed unlikely to gain enough steam early Friday to strike as a hurricane. The storm's failure to gain the kind of strength in the Caribbean that forecasters initially projected made it more likely that Isaac won't become a hurricane until it enters the Gulf of Mexico, said Eric Blake, a forecaster with U.S. National Hurricane Center in Miami. (AP Photo/Dieu Nalio Chery)